PHP Code:
if (mysql_num_rows($sqlCheckUser == "0") || mysql_num_rows($sqlCheckPass == "0")
That part is wrong, you are doing a test inside a function argument. Replace that with the following:
PHP Code:
mysql_num_rows($sqlCheckUser) == 0
Roxy is right also, you should have
PHP Code:
or die(mysql_error())
after each mysql_query statement also. However if it is a production system, you should really just do die('sorry, mysql error') or something like that so you don't spit sql statements to the client